Aberdeen v St Mirren preview
McGinn has missed the last two matches with a hamstring strain but the Northern Ireland international trained on Monday and could return.
However, defender Clark Robertson (thigh), skipper Russell Anderson and midfielder Ryan Jack (both knee) all remain sidelined.
St Mirren left-back Jeroen Tesselaar is a doubt for the Pittodrie clash after going off against Celtic at the weekend with a tight hamstring.
Ellis Plummer, Adam Drury, Gary Teale and Isaac Osbourne all missed the 2-1 defeat by the champions through injury and are hoping to return but striker Steven Thompson (groin) remains a long-term absentee.